1. Field of the Invention
The present invention relates to a leg-portion attachment structure for movably supporting to-be-mounted main bodies of an image forming apparatus, an electric/electronic apparatus, and the like, and relates to an image forming apparatus provided with the leg-portion attachment structure.
2. Description of Related Art
Some main bodies of image forming apparatuses, electric/electronic apparatuses, and the like are provided with casters. When a heavy image forming apparatus difficult to carry by hand is carried in and out from, for example, an office, or is moved in the office, the image forming apparatus is easily moved by means of the casters.
For example, four casters are respectively provided at four corners of a bottom surface of an apparatus main body of the image forming apparatus or the like. Each of the casters is provided with a shaft portion to which wheels are attached and a flange portion which is attached to the bottom surface of the apparatus main body, the shaft portion being rotatably held by the flange portion. By push of the apparatus main body, the image forming apparatus can be easily moved (Japanese Patent Application Laid-open No. 2006-30787).
Further, the apparatus main body rocks when the image forming apparatus is moved by means of the casters. In order to prevent the rocking, rubber wheels are used as the casters, or the casters are attached to the apparatus main body while springs or rubber blocks are interposed between the apparatus main body and the casters.
As a technology for interposing the springs or the rubber blocks, for example, there has been disclosed a technology for stretchably interposing a compression coil spring between a bracket attachable to an apparatus main body and a flange portion for rotatably holding a caster (Japanese Patent Application Laid-open No. 2001-277808). Further, there has been disclosed another technology for interposing a compression rubber block between a bracket attachable to an apparatus main body and a flange portion for rotatably holding a caster (Japanese Patent Application Laid-open No. 2001-158204). By the above-mentioned technologies, in accordance with a force which is applied to the caster from a floor surface, the compression coil spring shrinks or the compression rubber block is compressed. As a result, rocking of the apparatus main body is suppressed. Further, when the rubber wheels are used as the casters, the rubbers of the wheels are compressed in accordance with a force which is applied to the wheels from the floor surface. As a result, the rocking of the apparatus main body is suppressed.
However, interposition of the coil springs or the rubber blocks between the apparatus main body and the casters as disclosed in the above-mentioned technologies has led to problems of upsizing and increase in cost of the apparatus. Further, load of the apparatus main body is much larger in the case of an image forming apparatus such as a large copier, and hence a high impact force acts on the casters when the apparatus main body starts to be moved. In order to absorb the impact force and support the load of the apparatus main body, it is necessary to use a rubber material excellent in load bearing properties and having a high elastic coefficient for the rubber wheels, which has led to such a problem that the wheels are expensive.